1. Field of the Invention
This invention relates to electrical outlet boxes and box supports particularly adapted for installation into indoor walls comprised of metal support framework.
2. Description of the Prior Art
The walls of indoor rooms of buildings are generally constructed of front and rear flat rigid panels spaced four to six inches apart about a supporting framework comprised of upper and lower horizontal beams and a series of beams extending vertically between said horizontal beams. The wall space, namely the space between the panels, generally accommodates thermal insulation, plumbing components and electrical wiring. The wiring typically extends from a power source to outlet boxes which house electrical receptacles or switches.
The electrical outlet boxes are recessed into the wall space so as to fit flush with the exterior face of the associated front wall panel. In those instances where the supporting framework is of wooden construction, as is typical of residential dwellings, the outlet box is usually installed by nailing to an appropriate vertical beam at a measured height above the lower horizontal beam. The outlet boxes are generally installed either at a low location of about 18″ above the associated floor, to accommodate plug-in receptacles that receive electrical cords, or are installed at a high location of about 53″ above the floor to hold switches that control electrical circuits.
Commercial and industrial buildings predominantly employ metal wall-supporting frameworks instead of the wooden framework prevalent in residential buildings, and the panels are usually of gypsum board or equivalent fire-resistant materials. Said panels may be employed in varied thicknesses of between about ½″ and 1½″. The outlet boxes employed with metal wall systems are of substantially the same construction as outlet boxes employed for wooden wall structures, however, the manner of positioning and affixing the outlet box in metal wall systems is considerably different than techniques typically employed with wooden wall systems.
Most contractors use prefabricated components to reduce the amount of time required to install outlet/switch boxes in a commercial or industrial building. In a typical on-site installation, a commonplace metal outlet box of 4″ or 4 11/16″ square size is attached with screws to a supporting panel. At low sites intended to receive plug-in receptacles, said supporting panel is of elongated shape, extending in attachment between the lower beam and a horizontal strut joined to contiguous vertical beams. The wires of a power cable are attached to the receptacle or switch within the box, and a “plaster ring” is attached to the supporting panel to cause the installation to fit flush with the exterior face of the wall. Such manner of installation is time-consuming because it requires the alignment of many pairs of holes and rotation of screws. In the course of construction of a new building which may require the installation of hundreds of outlet boxes, the cumulative working time is a significant economic factor.
It is accordingly an object of the present invention to provide an electrical outlet box assembly that can be rapidly and accurately installed.
It is another object of this invention to provide an electrical box assembly of the foregoing object which is compatible with standard components of metal wall frameworks.
These objects and other objects and advantages of the invention will be apparent from the following description.